1. Field of the Invention
This invention relates to water-resistant polymeric coatings or films, and highly-swellable polymeric gels, and, more particularly, to such products prepared from non-continuous, polymeric compositions having two phases therein, by further crosslinking or blending of a proteinaceous compound during a post-treatment polymerization or process.
2. Description of the Prior Art
Polymeric compositions of vinyl lactam monomers generally are one-phase, soluble, high viscosity materials. These compositions are found in a variety of commercial applications such as film formers, dye transfer inhibitors, rheology modifiers, extrusion components, dispersants, delivery systems, excipients, and drug delivery. Aqueous gels of these monomers can also be prepared by light covalent or associative crosslinking of polymer chains resulting in a highly-swellable, one-phase material of high viscosity. Such compositions are effective thickeners for use in personal care formulations such as hair care products.
The prior art is represented by the following:
Niessner, in U.S. Pat. Nos. 5,149,750 and 5,180,804, disclosed finely divided, water-swellable gel-like, water-swellable copolymers by polymerization of comonomers in the presence of a surfactant.
Liu, in U.S. Pat. No. 5,997,855, described a homogeneous terpolymer for hair care use, however, without a crosslinking agent.
Kopolow, in U.S. Pat. No. 5,130,121, described personal care compositions containing a stabilized cosmetically-active product obtained by in situ polymerization of a water-soluble vinyl monomer in the presence of discrete microdroplets of a cosmetically-active oil in water.
Blankenburg, in U.S. Pat. Nos. 5,635,169 and 6,107,397, described uncrosslinked aqueous copolymer dispersions of nonionic water-soluble monomers with N-vinyl groups, and hydrophobic monomers.
Steckler, in U.S. Pat. No. 3,878,175, disclosed highly absorbent spongy gel polymer materials by simultaneously copolymerizing and partially crosslinking a comonomer mixture of an alkyl acrylate and a heterocyclic N-vinyl monomer containing a carbonyl functionality in the presence of a hydrophobic liquid diluent in which the final polymer is insoluble.
Markus, in U.S. Pat. No. 2,810,716, described a process for making swellable resins by copolymerizing suitable monomers in the presence of a water-soluble non-redox divalent-ion containing salt.
Tseng, in U.S. Pat. Nos. 5,393,854 and 5,717,045, disclosed a one-phase, aqueous gel of crosslinked copolymers of vinyl pyrrolidone and dimethylaminoethyl methacrylate for use in hair care products. The crosslinking agent was 1-vinyl-3-(E)-ethylidene pyrrolidone. The gels had a Brookfield viscosity of between 60,000 and 100,000.
These references illustrate the desire of the art to produce a continuous network of polymer molecules, or microgel which is a one-phase system, and of high viscosity.
As described in the aforementioned co-pending U.S. patent applications, in contrast to this art, a new and improved aqueous polymeric composition was obtained which is a non-continuous polymeric composition having two-phases therein, particularly made up of a water-soluble polymer and in situ-formed, substantially water-insoluble resinous particles of the polymer substantially uniformly dispersed therein, and water or alcoholic solution. This polymeric composition is made by polymerizing a water-soluble vinyl lactam monomer with a predetermined amount of a crosslinking agent, and water, at a selected temperature, while periodically adding an initiator to the reaction mixture.
A particular application for such polymeric compositions is in color ink-jet printing. The advent of color inkjet printing has been instrumental in fueling the print-on-demand revolution and has also created a number of challenges. Often, the surface of the desired media does not possess the necessary properties for accepting the ink-jet ink. This results in long dry times and/or a poor ink-jet image. It has long been recognized that a surface treatment or media coating plays a critical role in the final print quality. Numerous media coatings are known in the art. They may contain any number of components and often consist of more than one layer. These ink-receptive coatings generally contain at least one hydrophilic polymer; often poly(vinylpyrrolidone) (PVP). In contrast to the teaching of the thickener art for personal care products, networked, highly swellable polymeric systems are undesirable in this application. Soluble PVP brings many benefits to properly formulated media coatings including rapid ink dry time, excellent print quality, highly resolved circular dots, and high, uniform optical density. Furthermore, copolymers of vinylpyrrolidone (VP) along with other suitable comonomers, such as dimethylaminoethyl methacrylate, acrylic acid, or vinyl acetate, have been used separately or in conjunction with PVP, to further optimize performance. Unfortunately, their resistance to water penetration can be weak. It is desired to provide long-term, excellent water-resistant qualities for such films.
Accordingly, it is an object of the present invention to provide a post-treatment composition and process for two-phase, aqueous polymeric compositions which can provide advantageous water-resistant polymeric coatings or films, or optionally, a highly-swellable polymeric gel.
A specific object of the invention is to provide a post-polymerization of such two-phase composition by further polymerization with additional crosslinker, to provide the desired water-resistant color inkjet-receptive film coated with the defined post-treated polymer composition of the invention, which film is capable of being printed from a color ink-jet printer to form superior water-resistant color images thereon.
Another specific object of the invention is to provide a post-treatment of such two-phase composition by further blending with an additional proteinaceous compound, to provide the desired water-resistant color inkjet-receptive film coated with the defined post-treated polymer composition of the invention, which film is capable of being printed from a color ink-jet printer to form superior water-resistant color images thereon.